Fats, lipids or triglycerides, as chemists call them, are essential to human life and health. Uninterrupted metabolism in the body is possible only if the balance of fats, proteins and carbohydrates is maintained. The first ones have a complex composition and are divided into several varieties. The structure of fats differs depending on the type, but each of them is important for the functioning of the brain and other organs.
Most people know from the school chemistry course what structure fats have.
Triglycerides are molecules containing higher carboxylic acids and glycerol esters that are insoluble in water.
They got their name due to the presence in the chemical composition of glycerin, which is also called trihydric alcohol.
The definition, properties, chemical composition, equation and formula of fats were described by French scientists at the beginning of the 19th century, who discovered that in the process of heating a mixture of water and fat, a reaction occurs, that is, the formation of glycerin, carboxylic acids. Typically, naturally occurring molecules contain three acid radicals and an even number of carbon atoms. It also contains saturated and unsaturated fatty acids. The first include the following:
The human body is mainly dominated by unsaturated fatty acids: oleic, palmitoleic, linolenic, linoleic, arachidonic. The lipid cell consists of almost 50% of oleic acid.
Experts identify the physical and chemical properties of fats. Lipids are light substances, the state of aggregation of which can be liquid or solid, depending on temperature. Even solid triglycerides become liquid when heated. Conversion time depends on composition and storage.
Since the molecules do not dissolve in water, the scientists concluded that they have a lower density. However, it is quite possible to dissolve lipids in ether, benzene and other organic substances. Partly dissolution occurs under the influence of ethanol.
Among the chemical properties of lipids, hydrolysis is distinguished, which is carried out by exposure to alkalis and mineral acids during heating. It is worth noting that high temperatures are not required for this process. In the human body, it occurs due to the effects of enzymes. As a result of hydrolysis, the fat molecule breaks down into glycerol and carboxylic acids.
If the splitting is carried out artificially, with the help of alkalis and other substances, the process is called saponification. Hydrogenation is another chemical property of fats. The reaction is the addition of a hydrogen molecule to the residues of unsaturated carboxylic acids contained in vegetable oils. As a result, liquid lipids become solid. This product is called salomas (combined fat).
A peculiar side effect of hydrogenation is an increase in the proportion of trans fats in the oil, which can be formed by exposure to certain molecules. These elements are considered harmful and often provoke various diseases when consumed regularly.
The classification of fats involves their separation depending on the origin, consistency, chemical composition. Taking into account the origin, animal and plant types of lipids are distinguished. They are considered natural, since it is in nature that you can meet animals and find plants from which fat is obtained.
Animals include fat obtained from marine life, land animals and birds. To vegetable – a product obtained by processing seeds or fruits of plants. Taking into account the state of aggregation, solid and liquid lipids are isolated. The former are usually animals, the latter are vegetable. There are also combined varieties that cannot be attributed to one of the groups, for example, pork fat.
Depending on the chemical structure, three groups of triglycerides are distinguished:
- limiting, a characteristic feature of which will be the presence in the composition of the residues of saturated higher carboxylic acids;
- unsaturated consist of unsaturated carboxylic acids;
- mixed have both varieties.
Unsaturated lipids can be polyunsaturated or monounsaturated. Among the limiting fats, cholesterol is distinguished, which today is considered one of the most harmful components of food. Cholesterol can be good or bad. The latter helps the body to function smoothly, the former leads to the development of serious diseases, such as atherosclerosis.
The functions of fats in the human body are varied. They play an important role in all processes. With their lack, metabolism is disturbed, symptoms of various diseases appear. The most important functions will be the following:
- The energy function is considered to be the main one. Scientists have found that carbohydrates are the main source of energy, but if it is impossible to get them, the fat reserve is used as a reserve food. Due to their high energy value, which is approximately 9 kcal per 1 g, lipids help to maintain performance even in the absence of food for a long time.
- Transport – plays an important role in the body. There are several fat-soluble vitamins that simply cannot be absorbed in the absence of lipids in the diet (D, E, K, A). When fat intake is limited, the body is deficient in nutrients.
Lipids form an energy reserve in the body in the form of a certain amount of subcutaneous fat. With a shortage of food, this reserve ensures the work of internal organs and systems. In women, the percentage of subcutaneous fat is higher.
- The thermoregulatory function is to maintain an optimal body temperature. This is due to the poor conductivity of fats, which prevent the body from hypothermia and overheating.
- The protective function of lipids is very important. Around each internal organ, you can see a kind of capsule consisting of fat cells. It provides amortization of organs, prevents their displacement and protects against injuries.
- Lipids are involved in the formation of cell membranes, nerve tissues and brain matter.
- One of the most important functions of fats is to participate in the production of hormones. Testosterone, prostaglandins, insulin are formed when a sufficient amount of lipids are consumed. Due to their many beneficial properties, triglycerides are considered no less important substances in the human diet than proteins and carbohydrates.